The left upper extremity and breast are drained by the axillary lymph node. The kidney is drained by the thoracic duct. The heart has its own lymph system going on surrounding the heart.
The mass described is in the posterior mediastinum (see images below). The thoracic duct is damaged โnear the massโ, hence drainage of organs distal to that point will be affected. The images below should clarify.
headshot
Mediastinal relations.
for anatomy dummies like myself
Thoracic duct relations.
This was the picture that I liked the most for this question. If you imagine that the injury is at the level of the left subclavian vein (LSV) and thoracic duct (TD) crossing each other, maybe it will help you realize that the left breast & left upper extremity bypass the injury. The right lung is drained by the right lymphatic duct, not the TD (see one of the links bellow). And the heart is where eventually all the drainage is going to end up to be pumped again (TD -> LSV -> SVC -> heart).
submitted by โonyx(46)
Thoracic duct relations.